﻿using System;
using System.Collections.Generic;
using System.Text;

namespace Calculator
{
    public class Operator
    {
        public double num1 { get; set; }

        public double num2 { get; set; }

        public virtual double GetResult()
        {
            return -1;
        }
    }

    public class AddOperator : Operator
    {
        public override double GetResult()
        {
            return num1 + num2;
        }
    }
    public class SubOperator : Operator
    {
        public override double GetResult()
        {
            return num1 - num2;
        }
    }
}
